Welding apparatus



Jan; 2, 1934. A vG|| BERT 1,942,055

WELDING APPARATUS Filed June 21, 1932 Inventor:- Ralph Afiilbert,

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His Att 0 rney.

Patented Jan. 193.4

1,942,055 WELDING APPARATUS Ralph A. Gilbert,

Plttsfleld, Mass; assignor to General Electric Company, a corporation of New York Application June 21, 1932. Serial No. 618,445 6 Claims. {01. Z a-s) My invention relates'to arc welding and more particularly to that form of arc welding in which the work is subjected to the action of are maintained between a plurality of electrodes.

- When operating thus with the arc in contact with the work there is a voltage between each electrode and the work even though the work is not connected in the welding circuit. This voltage increases and decreases as the distance between work increases and decreases.

It is an object of my invention to provide means for automatically controlling the position of thethe work.

My inventionwill be better understood from the following description taken in connection with the accompanying drawing which diagrammatically illustrates one embodiment thereof.

In the particular arrangement illustrated a plurality of electrodes 1 and 2 areconnected by conductors Band 4 to a source of welding current, not shown. These electrodes are held by supports 5 and 6 with their arcing terminals within arcing distance of one another and the work 7, In the particular arrangement illustrated, support 6 is fixed and support 5 is mov-" able, being attached to one end of a bell crank lever 8, the other end of which is provided with a finger piece 9. This lever is pivoted at 10 and normally biased into engagement with a stop 11 which determines the separation of the electrodes by positioning support 5 relative to support 6-. The operator by depressing finger piece 9 can rotate lever 8 about pivot '10 and bring the electrodes into engagement with one another by displacing support 5 toward support 6. when the bell crank lever is then permitted to swing backto'theposition illustrated, the electrodes are separated and an arcis struck between them.

.Electrodeskl and 2 are fed toward and away from one another and the work by reversible feed motors 12 through the agency or speed reducing gears 13 and feed rolls 14. The feed motors may be connected to a source of supply 15 through conductors 16, their fields'l'l, contacts 18 and 19 and conductors 20 for onedirection of rotation or through conductors 16, their fields 21, contacts 19 and 22 and conductors 20.10! the reverse directionof rotation. The connection of feed motors 12 to source of supply 15 is determined by the the, arcing terminals of the electrodes and the action of these springs is energized by feed the electrode toward -ble to apparatus desi ned for the movement of contacts 19 into and out of engagement with contacts 18 and 22. Contacts 12am supported on. armatures 23 of voltage relays 24 whose operating coils 25 are connected through conductors 26 and resistances 27 to the electrodes and the work '7 so as to be responsive to the voltage between these electrodes and the work. Mow able contacts 19 are biased into engagement with fixed contacts 18 by springs 28 and are moved into engagement with fixed by the energization of coils 25 when the voltage between the electrodes and the work '7 attains a predetermined value determined by the adjustment of resistances 2'7. The voltage 'difierence. between the electrodes andthe work '1 varies as the distance between their arcing terminals and the .work and the arrangement thus provided constitutes means for and 2 at a predetermined When the arcing. termin of either electrode "is displaced from the work sufficiently to generate a voltage great enough.- to move contact 19 into engagement contact 22 the feed motor 12 a-circuit completed through'fleld 21 and operates the feed rolls 14 in a direction to .the work. This feeding operation continues. until a predetermined voltage and separation of the electrode from the work has' been attained'when the movable contact 19 moves to the position-illustrated in the drawing. 11 the arcing terminal of either electrode approaches too close to the work 7, the feed motor 12 is energized through contacts 18 and 19 of relay 24 to complete its circuit through iield o 17 and rotatesinthe opposite direction, withdrawing the electrode from the work.

It is to be lmderstood, however; that in ac- 'cordance with my invention other feeding means between the electrodes responsive to the voltage and the work may be employed for positioning the arcing terminals of the electrodes a predetermined distance from the work when operating with the are established between the electrodes in contact with the work. Y 1 Preferably the electrodes are inclined to one another; as illustrated in the drawing, to deflect the are into engagement with the work by means of the magnetic field established between them. The electrodes may be tions relative to one another and .the .arc' be.- tween them deflected toward the work by electromagnets or jets of gas. Various gases may be used, and my invention is particularly'applicautilization of 110 contacts 22 against the o5 arranged in other posiare core 29 come electric arc is dissociated into its atomic state and when directed into engagement with the part to be welded recombines to its molecular state; liberating enormous amounts of heat. The utilization of atomic hydrogen flames is disclosed and claimed broadly in the copending application 01' Irving Langmuir, Serial No. 729,185, filed July 30, 1924, for Heating processes and apparatus, which application is assigned to the same assignee as the present application.

Referring to the drawing, the electric arc appears as there illustrated to have a core portion 29 which is surrounded by a flame 30 which is ir-; regular in shape and in constant motion. When a combustible gas is supplied to the arc, such,'for example, as hydrogen, the gas, flame and the'arc flame intermingle and are ditficult to distinguish from one another. In order to attain the regulation above described it is not necessary that the into direct engagement with the work since a voltage will appear between the electrodes and the work if the arc flame is in engagement with the work. 'Ihearc discharge may extend a short distance beyond the flame and consequently my apparatus may function with the visible 'part of the are out of engagement with the workthough' as a matter of fact I the arc is in engagement with the work.

My invention is applicable to direct current welding as well as to alternating current welding and single phase or polyphase alternating current may be employed. With polyphase alternating current each electrode is connected to one of the phase conductors and is controlled by a; feed motor, as described above in connection with the arrangement illustrated, which is suit able for direct current welding or single phase alternating current welding.

Although I have described my invention in connection with arc welding apparatus, it is to be understood that it is applicable to other arrangements in which an article is heated by an arc established between a plurality of electrodes is???- rected onto the article in any suitable manner.

What I claim as'new and desire to secure by Letters Patent of the United States is:

1. Apparatus comprising a plurality of electrodes, means for maintaining an are between said electrodes, means for directing said are onto electrode toward and away from said article in response to the voltage 'between said electrode and said article.

2. Apparatuscomprising aplurality of electrodes,- means for maintaining an arc between said'electrodes, means for" directing saidare onto ently feeding each an article to be heated, and means responsive to the voltage between said electrodes and said atticle for maintaining the arcing terminals of said 'and the work, and means responsive to the voltage between said electrodes and the work when operating with the arc in contact with the work for positioning the arcing terminals of said electrodes a.- predetermined distance from the work.

4. Welding apparatus comprising a plurality of electrodes, means for supportin'gisaid elec-' trodes with their arcing terminals within arcing distance of one another and the work; means for maintaining an are between said electrodes and means for independently feeding each electrode toward and away' from the work in responseto the voltage between said electrode and the work.

5. Welding apparatus comprising a plurality of electrodes, .means for supporting said electrodes in inclined other with their arcing. terminals within arcing distance of one another andthe work, means for maintaining an are between said electrodes, and means responsive to. the voltage between said. electrodes and the work when operating with the arc in contact with .the work for maintaining a predetermined arcing condition between said electrodes and the work.

6. Welding apparatus comprising a plurality of electrodes, means for supporting said electrodes with their arcing terminals within arcing distance of one another and the work, means for maintaining an are between said electrodes'and means responsive to the voltage between said electrodes and the work when operating with the arc in contact with the work for maintaining a predetermined arcing condition between said electrodesand the work.

RALPH A. GILBERT.

electrode at a predetermined distance from said Ill- 

